Reduction of ventilatory time using the multidisciplinary disconnection protocol. Pilot study*

Objective: compare ventilatory time between patients with the application of a disconnection protocol, managed in a coordinated way between doctor and nurse, with patients managed exclusively by the doctor. Method: experimental pilot study before and after. Twenty-five patients requiring invasive mechanical ventilation for 24 hours or more were included, and the protocol-guided group was compared with the protocol-free group managed according to usual practice. Results: by means of the multidisciplinary protocol, the time of invasive mechanical ventilation was reduced (141.94 ± 114.50 vs 113.18 ± 55.14; overall decrease of almost 29 hours), the time spent on weaning (24 hours vs 7.40 hours) and the numbers of reintubation (13% vs 0%) in comparison with the group in which the nurse did not participate. The time to weaning was shorter in the retrospective cohort (2 days vs. 5 days), as was the hospital stay (7 days vs. 9 days). Conclusion: the use of a multidisciplinary protocol reduces the duration of weaning, the total time of invasive mechanical ventilation and reintubations. The more active role of the nurse is a fundamental tool to obtain better results.


Introduction
Mechanical ventilation (MV) is one of the most commonly techniques used in Intensive Care Units, and its disconnection is one of the most evaluated procedures based on scientific evidence (1)(2)(3)(4)(5) . Currently, the invasive mechanical ventilation (IMV) removal process occupies about 40% (1,(6)(7)(8) of the total ventilatory support time, representing a great difficulty for both the patient and the professional. The more difficult are to remove ventilatory support, the greater the chances of suffering complications such as airway trauma or nosocomial infection, among others, which in turn would lead to an increase in hospital stay, costs or mortality, also having repercussions on the patient's quality of life (6) , reasons to try to shorten ventilatory time.
The use of disconnection protocols brings efficacy to daily clinical practice and avoids individual judgement based on one's own experience, reducing variability in the disconnection process (4,9) . It is possible to reduce the total duration of mechanical ventilation in 26% and the stay in the Critical Care Unit in 11% without repercussions in patient's morbidity and mortality (9) with the application of release protocols, considering how important is the role of the nurse within the process, contributing to improvements in the reduction of the stay in hospital (3,10) .
However, despite the published data, the disconnection of IMV remains a process with a lack of consensus (9) , and this is why the research in this field is justified.
Our main objective was to compare ventilatory time between patients with the application of a disconnection protocol managed in a coordinated way between doctor and nurse versus patients managed exclusively by the doctor. Our secondary objectives were to compare the rate of reintubation between the two cohorts, to compare the duration of weaning, and to compare the days of stay in the unit between the two groups of patients.

Method
An experimental before and after pilot study was carried out in the Resuscitation Unit of the Hospital General Universitario de Elche, which consists of six critical care beds for surgical patients. This pilot study was performed to verify if the mechanical ventilation disconnection protocol managed in a multidisciplinary way was effective and with the intention to continue later a multicenter study of cases and control, if the results were favorable. The ethics committee of the Hospital General Universitario de Elche approved the work, and informed consents were obtained from the relatives of the patients who were included in the prospective group.
Before starting the study, two half-hour meetings were held to explain the study, the protocol, how to carry it out and how to complete the data collection notebook. In addition, the research team was available to answer questions from both the medical team and the nursing team. The data collection notebook was the only instrument used for the collection of information.
All patients over the age of eighteen who were admitted in the Resuscitation unit, who required IMV for a period greater than or equal to 24 hours, who were extubated, and who had either signed the informed consent form to participate in the study, or their relatives, were included. All patients who died during the period of MV and those who ended up tracheostomized after a period of MV were excluded.
Successful weaning was considered when the patient was able to remain breathing without invasive support for a period greater than or equal to 48 hours (5,7-9,11-12,22-23,25) .

Results
Twenty-five patients were included in the study, nine in the prospective group and sixteen in the retrospective group. In the retrospective data, nine patients who could not enter in the weaning phase because they were underwent a tracheostomy and one patient due to death were discarded, while in the prospective data there was no loss. The variables studied and their comparison are shown in Table 1. It is important to note that both groups had a high comorbidity index (94% vs 89%), which also correlates with a high ASA classification (18% vs 45%), and an age above 70 years.
As for the characteristics most closely related to IMV, the most significant difference between the two The time to start weaning was longer in the prospective group, and the same occurred with the stay in the unit.
The rate of reintubations was lower with the application of a multidisciplinary protocol.

The differences found in the variables analyzed
were related to the application of the multidisciplinary protocol. In the retrospective group, the most used ventilatory mode was Synchronized Intermittent Mandatory Ventilation or SIMV (70%) versus C/A (100%) in the prospective group as shown in Table 2.
Ventilation times with O2 in T also varied between the two groups, with a predominance of times greater than 2 hours in the case of the retrospective cohort (

Discussion
The study attempts to reflect a reality in the According to Cochrane (9) , with the implementation of weaning protocols, the hospital stay in the critical care unit is reduced by 11%. Gupta et al. (13) applied protocols to patients with simple and difficult weaning; obtaining an average of stay in unit between 12 and 26 days. In our case, the time of stay in the unit was shorter in the group to which the protocol was not applied, probably due to the associated comorbidities www.eerp.usp.br/rlae criteria. In previous studies (3,(9)(10)22,(26)(27) , it is shown how the application of protocols influences in the reduction of the time that the process lasts, diminishing the time of weaning in a 70% (9) and the total time of mechanical ventilation in a 26% (9) . In our case, we reduced weaning time by almost 17 hours, a number very similar to that obtained in previous studies (10) and the total mechanical ventilation time by approximately 29 hours, a number that also approximates that obtained in previous publications (3) . In the retrospective group, after theoretically developing the weaning protocol and based on the bibliography regarding the improvement of quality and results after the application of these protocols, it did not seem ethical to us to propose a control group that would not be benefited by this improvement.
Due to the great advance represented by the inclusion of this work in our unit and the improvements obtained in the time of mechanical ventilation, it was decided to continue with the study in order to obtain a larger and more representative sample of patients that will allow in the future obtaining results that are more conclusive.

Conclusion
With the implementation of a disconnection protocol carried out in a multidisciplinary way and giving a leading www.eerp.usp.br/rlae